Per Service Egress Link Selection

1. A system comprising: a storage device for storing instructions; and a processor configured to execute the instructions to: access a network packet having a network packet destination, the network packet being associated with a service; maintain a service-specific routing table distinct from a Border Gateway Protocol (BGP) routing table, the service-specific routing table including a list of service peering routers for use with the service; select a peering router through which the network packet is to be routed from the service-specific routing table based on the service associated with the network packet; and encapsulate the network packet in an encapsulating packet, the encapsulating packet specifying the selected peering router as an encapsulating packet destination.

2. The system of claim 1 , wherein the encapsulating packet is a Generic Routing Encapsulation (GRE) packet, an IP-IP packet, a Multiprotocol Label Switching (MPLS)-tagged packet, or a Virtual Local Area Network (VLAN) packet.

3. The system of claim 1 , wherein the processor is further configured to: select an egress port on the peering router based on the service, and add an egress port identifier to the encapsulating packet, the egress port identifier identifying the selected egress port.

4. The system of claim 3 , wherein the egress port identifier comprises a Multiprotocol Label Switching (MPLS) label included in the encapsulating packet.

5. The system of claim 3 , wherein the egress port identifier comprises a Virtual Local Area Network Identifier (VLAN-ID).

6. The system of claim 3 , wherein: the service-specific routing table maintains the list of service peering routers in association with respective service peering router egress ports for use with the service, and the peering router and the selected egress port are chosen from the list of service peering routers and respective service peering router egress ports.

7. An electronic device implemented method comprising: accessing a network packet having a network packet destination, the network packet being associated with a service and encapsulated in an encapsulating packet having a specified peering router as an encapsulating packet destination; maintaining, in a service-specific routing table distinct from a Border Gateway Protocol (BGP) routing table, a list of service peering routers and service peering router egress ports for use with the service; selecting a peering router egress port which the network packet is to use when exiting the peering router, the peering router egress port selected from the list of service peering routers and service peering router egress ports based on the service associated with the network packet; and adding an egress port identifier to the encapsulating packet, the egress port identifier specifying the peering router egress port.

8. The method of claim 7 , wherein the encapsulating packet is a Generic Routing Encapsulation (GRE) packet.

9. The method of claim 7 , wherein the egress port identifier comprises a Multiprotocol Label Switching (MPLS) label, a Virtual Local Area Network Identifier (VLAN-ID), a Generic Routing Encapsulation (GRE) tag, or an IP-IP tag included in the encapsulating packet.

10. The method of claim 7 , wherein selecting the peering router egress port based on the service comprises analyzing a link associated with the peering router egress port, the link being part of an advertised route for routing network traffic, and the analyzing comprises evaluating: a capacity of the advertised route, a utilization of the advertised route, a cost of an alternative to the advertised route, or an end-user of the network packet.

11. A non-transitory electronic device readable storage medium holding instructions that, when executed, cause a processor to: access a network packet having a network packet destination, the network packet being associated with a flow or user connection; maintain a service-specific routing table distinct from a Border Gateway Protocol (BGP) routing table, the service-specific routing table including a list of service peering routers for use with the flow or user connection; select a peering router through which the network packet is to be routed, the peering router selected from the service-specific routing table based on the flow or user connection associated with the network packet; and encapsulate the network packet in an encapsulating packet, the encapsulating packet specifying the selected peering router as an encapsulating packet destination.

12. The medium of claim 11 , wherein the encapsulating packet is a Generic Routing Encapsulation (GRE) packet.

13. The medium of claim 11 , further holding instructions that, when executed, cause a processor to: select an egress port on the peering router based on the flow or user connection, and add an egress port identifier to the encapsulating packet, the egress port identifier identifying the selected egress port.

14. The medium of claim 13 , wherein the egress port identifier comprises a Multiprotocol Label Switching (MPLS) label included in the encapsulating packet.

15. The medium of claim 13 , wherein the egress port identifier comprises a Virtual Local Area Network Identifier (VLAN-ID).

16. The medium of claim 13 , further holding instructions that, when executed, cause a processor to: maintain in the service-specific routing table a list of service peering router egress ports for use with the flow or user connection, and the peering router and the selected egress port are chosen from the list of service peering routers and service peering router egress ports.